1. Field of the Invention
The present invention pertains to the art of household appliances and, more particularly, to a variable volume signaling device for conveying to an operator of the appliance both the activation of user input controls and when the appliance reaches a predetermined operational stage.
2. Discussion of the Prior Art
Essentially all household appliances, including microwave ovens, ranges, dishwashers, washing machines, clothes dryers and the like, are provided with user input controls for use in selecting desired operating parameters of the appliances. For instance, a microwave oven generally incorporates an electronic keypad having both numeric and function control buttons which enable a user to select desired operation cycles, such as defrost or cooking cycles, and to also input activation time periods. Typically, a user would be provided with some type of feedback signal as a means of verifying when an engaged control button has been activated. Most commonly, an audible signal in the form of a short beep is produced to signify the pressing of each control button. In addition, it is common to signal the user when the selected operation cycle has been reached, such as an end of cycle feedback signal, by producing an audible signal which has a different tone, length or the like, as well as volume, from the key pressing signals. In the case of a microwave oven, this signaling generally takes the form of a series of louder beeps. In other types of appliances, such as clothes dryers, buzzers or tone generators are commonly utilized for this purpose.
Regardless of the type of audible signal produced, it is often desirable to adjust the volume level associated with such a signaling system. In certain appliance models, provisions are made for controlling the volume level of the signal indicating when a certain operational stage, such as an end of cycle condition, has been reached. However, it can also be desirable to vary the volume of the signals generated upon use of the keypad. Since the user will be situated at the appliance when inputting the desired cycle parameters and will generally be remote from the appliance when the cycle condition is reached, adjusting these volume levels evenly could result in the user being subjected to a somewhat ear splitting sound while operating the keypad. For at least this reason, audible signaling systems of the type described will generally have fixed volume signaling for the operation of the control pad, while some enable variances in the volume output for the operational stage signals. Although it would be possible to provide separate user input and operational stage signaling systems, each incorporating its own volume adjusting circuitry, such an arrangement would unduly add to the cost and complexity of the overall appliance.
Based on the above, there exists a need in the art of appliances for a signaling system which produces audible signals upon both the activation of user input controls and when the appliance reaches a certain operational stage, wherein the volume levels associated with each of the signals can be simultaneously adjusted at varying increments or rates.